H I G H W A Y R E S E A R C H B O A R D

Bulletin No. 36

uuemen i n

kOADEVY

R E S E A R C H

1951

HIGHWAY RESEARCH BOARD 1951

O F F I C E R S

Chairman -Vice-Chairman , Acting Director^

R . A. MOVER R . H . BALDOCK

. . . F R E D BURGGRAF

E X E C U T I V E C O M M I T T E E

THOMAS H. MacDONALD

H A L H. H A L E

L O U I S JORDAN

R. H . B A L D O C K

H. P. B I G L E R

P Y K E JOHNSON

B U R T O N W. MARSH

R. A. M O Y E R

F . V. R E A G E L

W. H. ROOT

C H A R L E S M. UPHAM

Commissioner, Roads

Bureau of Public

Executive Secretary, American Association of State Highway Officials

Executive Secretary, Division of Engineering and Industrial Research, National Research Council

State Highway Engineer, Oregon State Highway Commission

Birmingham, Alabama

President, Automot ive Foundation

Safety

Director, Safety and Traffic Engi­neering Department, American Automobile Association

Research Engineer, Institute of T r a n s p o r t a t i o n and Traffic Engineering, U n i v e r s i t y of California

Engineer of Materials, Missouri State Highway Department

Main tenance Engineer, Iowa State Highway Commission

Consulting Engineer

E D I T O R I A L S T A F F

Fred Burggraf W. N. Carey, Jr .

The Highway Research Board is not responsible for the statements made and opinions expressed in its publications.

P U B L I C A T I O N O F F I C E S

2101 Constitution Avenue Washington 25, D. C.

H I G H W A Y R E S E A R C H B O A R D

Bulletin No. 36

PAVEMENT MARKING

PRESENmO AT THE THIRTIETH ANNUAL MEETING

1951

HIGHWAY RESEARCH BOARD DIVISION OF ENGINEERING AND INDUSTRIAL RESEARCH

NATIONAL RESEARCH COUNCIL

Washington 25, D. C. May 19S1

DEPARTMENT OF TRAFFIC AND OPERATIONS

W i l b u r S m i t h , Chairman A s s o c i a t e D i r e c t o r , Bureau o f Highway T r a f f i c ,

Y a l e U n i v e r s i t y

COMMITTEE ON ROADWAY PAVEMENT MARKINGS*

A . R. L a u e r , Chairman P r o f e s s o r o f P s y c h o l o g y

Iowa S t a t e C o l l e g e

W i l l i a m G. E l i o t , S e c r e t a r y Bureau o f P u b l i c Roads

A. K. Branhan, J o i n t Highway Research P ro jec t , Purdue U i i v e r s i t y

Daniel Branigan, D i s t r i c t T r a f f i c Engineer, I l l i n o i s D i v i s i o n o f Highways

Leon 'Gorder, Senior Maintenance Engineer, Missour i State Highway Department

F. B. Crandal l , T r a f f i c Digineer, Otegon State Highway Comnission

Wi l l i am H. Goetz, Research Qigineer, I^lrdue U i i v e r s i t y

B. D. Greenshields, Professor o f C i v i l fiigineering, George Washington U i i v e r s i t y

Richard S. Hunter, C l i i e f Opt ica l &ig ineer , Henry A. Gardner Laboratory

John C. Koh l , Ass is tan t Professor o f Transpor ta t ion , U i i v e r s i t y o f Michigan

Burton W. Marye, J r . , Ass is tan t Cl i i e f Engineer, V i r g i n i a Department o f Highways

W i l l i a m J . M i l l e r , T r a f f i c and Planning Engineer, Delaware State Highway Department

Harry E. Neal , Chie f Engineer, D i v i s i o n o f T r a f f i c and Safety, Ohio Department o f Highways

H. J . Neale, Landscape Engineer, V i r g i n i a Department o f Highways

W. 0 . P r ice , &igineer , o f Safety and T r a f f i c , Iowa State Highway Comnission

A. W. Van Heuckeroth, Chief , Mater ia l s Branch, &igineer . Research and Development Laboratory

Charles R. Waters, D i s t r i c t &igLneer, New York State Department o f Pkiblic Works

C. C. Wiley, Professor o f Highway Qigineer ing, U i i v e r s i t y o f I l l i n o i s

F. Houston Wynn, Bureau o f Highway T r a f f i c , Yale U i i v e r s i t y

J . C. Young, T r a f f i c Engineer, C a l i f o r n i a D i v i s i o n o f Highways

*11iis Committee has sponsored the paper "Methods and Appl ica t ion Procedures f o r Pavement M a r k i n g " .

DEPARHMENT OF MATERIALS AND CO^iSlRUCTKm

P r o f e s s o r C. H . S c h o l e r , Chairman Head , A p p l i e d Mechan ic s D e p a r t m e n t

Kansas S t a t e C o l l e g e

' GENERAL MATERIALS D l V I S I O f

K . B . Woods, Chairnan A s s o c i a t e D i r e c t o r , J o i n t Highway R e s e a r c h P r o j e c t

Purdue U n i v e r s i t y

COMMITIEE (Xi PAINTS AND MARKING MATERIALS*

W i l l i a m H . G o e t z , C h a t r n a n Resea rch E n g i n e e r , Purdue U n i v e r s i t y

Fred H. Baumann, Supervising Engineer, Tes t ing Laboratory, New Jersey Striate Highway Department

Professor Fred J . Benson, Department o f C i v i l Qigineer ing, A g r i c u l t u r a l and Mechan­i c a l College o f Texas

H . F. Qenmer, &igineer o f Mate r ia l s , D. C &igineer Department W. J . Halstead, Bureau o f Publ ic Roads

Harry E. Neal, Chie f &igineer . D i v i s i o n o f T r a f f i c and Safety, Ohio Department o f Highways

M. A. Peterson, Ch ie f Chemist, Highway Department Laboratory, U i i v e r s i t y o f Minnesota

Dr. Leroy W. Shuger, Balt imore Paint and Color Works

Dr . W. G. Vannoy, P i g ^ t s Department, E. I . du Pont de Nemours and Company

S id Werthan, New Jersey Zinc Company

E. K. Ziunennann, D i r e c t o r , Technical Service Laborator ies , Titanium Pigpient Corporation

*T1iia Committee aponaored the paper 'Preaent Preferences f o r T r a f f i c Pa in t " .

COTITENTS Page

REPORT OF THE COMMITTEE ON PAVEMENT MARKINGS

A R L a u e r , Chairman 1

METH(»S AND APPLICATION PROCEDURES FOR PAVEMENT MARKING

C h a r l e s R Wate r s 1

PRESENT PREFERENCES FOR TRAFFIC PAINT G W Ashman 7

REPORT OF THE COMMITTEE ON ROADWAY PAVEMENT MARKINGS

A. R. Lauer, Chairman Professor of Psychology, Iowa State College

During the past year efforts have been made in four general directions; (1) verifying and publicizing the results of a survey made last year on line-striping practices in the various states, (2) analysis of methods and equipment used in applying center and barrier Imes, (3) collecting information on researches being carried out m this area, and (4) encouraging highway de­partments, experiment stations as well as colleges and universities to pursue research on various problems in this area.

The major effort of the Committee was focused on securmg specific m-formation on methods of striping from every state in the Union, a project in which every member took part and which was presented in an open meeting

of the Committee by Mr. Charles R. Waters of New York. Splendid coopera­tion was obtained from every state and i t is the feeling of the Committee that some very worthwhile information has been assembled.

Any study or compilation of facts or information must be considered as being relative in its application. For example, our study shows that 39 states use plain unreflectorized pamt for striping. The necessity for repainting varies from four months to three years with a median value around 12 months. This type of information must be tem­pered by judgment of the reader con­sidering the amount of traffic, climatic effects on paint, type of pamt used, type of surface pamted and even by the pressure of public opinion.

METHODS ,AND APPLICATION PROCEDURES FOR PAVEMENT MARKING

Charles R. Waters District Engineer, State Department of Public Works, Buffalo, N. Y.

SYNOPSIS

Contact was made with every highway department in the country, in addition to several foreign provinces and countries, with the request that a form containing 70 or more items relating to types of pamt, costs, methods of application, methods of protecting green paint, drying time, mixing of beads, when used, and other important aspects of pavement striping. The data are being put up in tabular and graphic form and will be presented as reported by the respective states.

Data on types, weight, cost and features of striping equipment will be presented. Reports were obtained from every state in the Union and some foreign countries.

Analysis of questionnaires indicates a growing uterest in marking traffic lines on pavements as a means of safety on highways. Steps toward unlfornuty throughout the United States are mdicated.

From 48 states reporting, 18 report that the stripers were designed and bult in their own shops, 29 report that stripers were purchased from commercial sources and one state reports that their markings are placed by a contractor. The Provmces of Mamtoba and Nova Scotia m Canada also contract for the placing of markings while Ontario, British Columbia and the Territory of Hawaii use purchased stripers.

Thirty states report using self-propelled units, mne trail the unit, eight use the push-mobile type and one did not report. Forty-four states use pressure nozzles while four

use the flow type. Thirty-eight states place preliminary markings for the equipment to follow while ten states do not.

Thirty-seven states plus four provinces reporting from Canada use reflectorized markings for increased night safety. Six states use non-reflectorized markings and five did not furnish definite information. Hawaii uses reflectorized markings. While a number of states place only reflectorized markings, the greater percentage also use plain paint, with the reflectorized markings used on main touring routes. No-Passing zones, troublesome intersections and railroad crossings at grade. The drying time of the pamt is reported as varying from 15 minutes up to 2 hours.

Of the 43 states using dash Imes, the length of the paint mark and the space between varies from a minimum of 9 - 15 ft. to a maximum of 70 - 70 ft. with 20 states using a 15 - 25 ft pattern. Most of the states have standardized on a four inch width marking although three report using a three inch line and one a six inch lue. By reason of using a dash lue, a saving in paint of from 50 to 80 percent is accomplished.

The cost of providing markings varies greatly according to quality of paint and applica­tion methods. Currently it is reported as varying between $13.00 and $63.00 for an unreflectorized Ime and between $25.00 and $80.00 for a reflectorized line Operational costs are greatly responsible for this variance, it being reported that a low of 5 miles and a high of 100 miles of pavement is painted a day.

The most recent s t u ^ by members of Project Committee No. 11 - Roadway Pavement Markings, Highway Research Board, has been completed. The Committee considered i t would be advantageous to assemble information from all states regarding pavement marking procedures. Accordingly, a questionnaire prepared by the Com­mittee was forwarded to officials of the State Highway Departments to be com­pleted and returned for tabulation. Contact was made with every State Highway Department, in addition to several foreign countries and a number of the provinces in Canada. The ques­tionnaire contained over 70 items re­lating to the types of equipment used, methods of application, drying time of pamt, use of glass spheres for night reflectance together with other pertinent and important aspects of pavement marking.

This report, prepared from the data obtained, is purely factual and is based on the points covered in the question­naire. The work of the present writer is that of compiling and tabulating the information collected by the regional sub-chairmen. No attempt is made in this report to evaluate the methods used in the various states, nor to make a judgment of evaluation on types or methods.

Some 36 states gave written state­ments that they are using the geometry or pattern of the system recommended

in the Federal Manual on Uniform Traffic Control Devices for Streets and Highways.

The data obtained from the question­naires have been tabulated in chart form for detailed study. Pertment informa­tion which is of principal mterest follows in the order indicated on the charts. *

EQUIPMENT USED FOR STRIPING

From 48 states reporting, 17 advise that stripers were designed and built m their own shops and 31 report that machines were purchased from com­mercial sources. The oldest of the stripers dates back to 1934, although 37 states or 77 percenf report using equipment purchased or built subsequent to 1946, and 16 states report using equipment which is not older than one year. It is assumed that new devices and improvements have been added to the old equipment from time to time.

There is a great variance in the weight and the cost of equipment. The minimum weight of any unit as reported is 175 lb. which is only the weight of striping device. It does not include truck, paint tanks and miscellaneous equipment. The maximum weight of any one unit which includes the truck attach­ed striper, tanks and all equipment is

'The charts are folded in at the end of this bulletin.

22,000 lb. From the reports, it is found that weights vary greatly accord­ing to type of equipment and the mileage to be pamted. In some states, one or two large umts cover the entire mileage while m others a number of small machines are employed.

While the cost of a shop-constructed striper whether pushed, pulled or moimted on the truck, may be relatively small, the cost of a commercial self-propelled unit, or truck mounted unit in which the truck cost is included, may seem to be exceedingly high.

COST OF PAINT AND PAINTING

The cost of pavement marking equip­ment I S reported as varying from a minimum of $700 to a maximum of $16,000. Small self-propelled units capable of placing only 5 to 10 miles of line per day are in the lower range, while the fully equipped heavy duty equipment capable of placing up to 60 to 70 per day costs in the upper brack­ets. The total cost of all equipment as reported in the questionnaires is $280,069.00, or an average of $5,600 per unit.

In analyzing the information furnished regarding the number of vehicles re­quired ui placing the markings, i t is found that, in general, the complete unit consists of either a self-propelled paint striper or a truck mounted striper and a service truck. The service truck in addition to carrying extra paint and supplies, picks up and returns to the paint striper the flags, blocks or other devices previously placed on the wet pamt line to protect it while drying.

WIDTH OF ROAD EQUIPMENT USED

The overall width of the stripers varies according to type. The mini­mum width is 2 f t . 8 in. for a self-propelled unit, the maximum width 9 f t . 6 in. for a striper attached to the side of a truck. An average of all reporting is between 6 and 7 f t . , which I S standard width for a truck of medium size. Only two states report widths exceeding 8 f t . , one 9 f t . and one 9 f t .

6 in. It appears that passing difficulty might be encountered when placing markmgs on a 16 or 18 f t . pavement when using a unit of excess width. In New York the Vehicle and Traffic Law prohibits the movement of vehicles having a width greater than 8 f t . .over public highways unless a special permit is issued.

The data show that 31 states use a self-propelled imit, 9 t ra i l the unit and 8 use the Pushmobile type. The self-propelled units include both commercial stripers operating under their own power and those mounted on trucks. The trailer type are those mounted m a framework running on low pneumatic tires towed immediately at the rear of the truck, and the Pushmobile types are those units built into a frame havmg both front and rear axles, pushed ahead of the paint truck.

PAINT CAPACITY OF STRIPERS USED AND PERSONNEL REQUIRED

IN LAYING

The number of paint tanks m use varies from 1 to 4 having a capacity as low as 12 gallons and as high as 700 gallons. The 12-gallon tank is contained on the small self-propelled unit with the 700 gallon tank mounted on a large self-propelled tmlt. Fourteen states report using one paint tank, 14 states use 2 tanks, 15 states use 3 tanks and 5 states use 4 tanks. Twenty-one states or nearly 44 percent use a 60-gallon tank apparently for ease in f i l l ing, cleaning and space requirements. From the 48 states, 26 transfer the paint to the tank by hand using a pail or the original 5-gallon container while the remaming 22 states transfer i t by either air pressure or mechanical pump. It appears that hand methods enter into the transferring of paint, and I t I S probable that if the pamt is pur­chased m standard 5-gallon pails, i t is emptied directly into the paint tank; if furnished in 30 or 60 gallon drums, the pump or air pressure method is used.

Pressure nozzles are used by 92 percent of the states, only 4 reporting the use of flow nozzles.

The personnel required to operate the stripers varies from one with the small self-propelled unit up to 11 on the large self-propelled units. In most cases, the questionnaire did not defmitely state whether or not the personnel included men for operating the service truck. From the average of all 48 states, 4. 5 men are required for a complete marking crew.

COST OF PRELIMINARY MARKING

Thirty-six states place preliminary markings for the guidance of the paint striper at a cost varying from 75 cents for center line and 70 cents for barrier line to $35 for center line and $15 for barrier line. Ten states do no pre­liminary marking and two states place preliminary markings only at certain locations. Replies were lacking from a number of states as to the cost of preliminary markings and 4 states reported no additional cost for placing the barrier line marks.

PROTECTION OF THE UNIT, DRYING, ETC.

For the protection and safety of the pamting unit, 20 states report using a police escort while 27 do not; one state did not report on this question. Other means of protectmg the unit include a car ahead to warn approaching traffic used by 9 states; signs or flagmen used by 22 states; and siren and flasher used by 5 states.

From 46 states reporting, 39 state that gaps are left in the markings at cross streets, 7 report in the negative; 27 report gaps left at cross roads while 20 report that markmgs are carried through the intersection.

The speed of travel of the marking equipment in miles per hour is reported to be from a low of 2 m. p. h. to a high of 20 m. p. h. The data show that 35 states, or 73 percent, traveled at a rate of from 5 to 10 m.p.h. Reports regarding the number of ,miles marked per day varies from 5 to 100. Thirty-six states, or 75 percent, report their equipment marks between 20 and 40 miles per day. A great many variables

such as type of equipment and drying time of paint enter mto the number of miles which can be pamted in a speci­fied number of hours.

ADDITIONAL COST IN TWO COLORS

In reply to the question on the addi­tional cost by reason of using two colors, one state reported' 25 cents per mile, one $1.65, one $5.10, one $9.30 and one $11.34. Six reported no ~ additional cost, two reported the additional cost to be negligible and the remaining states made no reply or do not use two colors.

From 42 states reporting on the question, "How many strips are re­quired to mark a two-lane highway?", 37 stated the marking is completed in one tr ip, one state reported one to two trips, two states reported two trips and two states reported three trips.

TIME BETWEEN PAINTING

From 39 states using plain unreflec-torized paint, one state reports the necessity for repainting every 4 to 6 months, four states repaint every 6 months, five states repaint every 6 to 12 months, one state repaints every 8 to 12 months, 18 repamt once a year, two repaint every 12 to 18 months, one repaints every 18 months, three repaint from 1 to 2 years, one repaints from 1 to 3 years, two repaint every 2 years, and one state reports that the time between repainting is variable. Traffic density, quality of paint and weather conditions dictate to a large degree the necessity for remarking the lines.

A variety of answers were received from 41 states reporting on the life of reflectorized markings either as a regular program or on an experimental basis. The most frequent repamting is reported as bemg every 6 months (only one state), the longest span between paintings, 3 years. A number of states report they are placed yearly but ten states definitely indicate an increase m the life of the marking by the use of reflectorized paint.

METHOD OF APPLYING REFLECTORIZED PAINTS

Regarding the method of placing re-flectorized markings, 24 states report using the pre-mix method, 39 use the beads on wet paint method and five use a combination of the two known as over­lay. Sixteen states use both the pre-mix and the beads on wet paint methods as a regular practice.

Al l except four states use either signs or protective devices to guard the wet pamt markings against tracking by vehicles during the drying period. The devices vary f rom simple home-made wooden blocks to cones, Z guards, and pyramids manufactured commercially. In 21 states, police patrol the wet paint line during the drying period. In 15 states motorists are liable to arrest for driving on wet paint.

DRYING TIME

The reported drying time for reflec-torized pamt varies between ten and 120 minutes depending upon the formulation, pavement c o n d i t i o n s , temperature, humidity and wind velocity. The greater percentage report the time as being between 20 and 40 minutes. Only two states report clogging trouble at the spray gun, all others stated they ex­perienced no clogging or only mmor difficulties.

Thirty-one states report good vis i ­bility of reflectorized paint before wear and 14 average visibility. The wearing quality is reported as good by 24 states, 16 report average wear, one reports variable wear, one average to poor and two poor.

LENGTH OF SEGMENTS PAINTED

Of the 43 states using dash lines, the length of the paint mark and the space between varies from a minimum of 9 f t . dash with 15 f t . gap to a maxi­mum of 70 f t . dash with 70 f t gap. From this number, 21 states or nearly 49 percent use a 15 f t . dash with a 25 f t . gap. Most of the states have standard­ized on a 4 in. width marking although one uses a 3 m . , one a 4-1/2 m . , two

use 5 i n . , and one uses a 6 in. width of line.

AMOUNT AND COST OF BEADS USED

Three states report using 4 lb. of glass spheres per gallon of paint, one state uses 4-1/4 l b . , two states 4-1/2 lb . , six states 5 l b . , one state 4 to 6 lb . , one state 5-1/4 lb . , three states 5 to 6 l b . , and 26 states or over 60 percent use 6 lb. per gallon of paint. A number of states purchase reflector­ized paint as a packaged product; about 6 lb. of beads furnished with each gallon of paint.

The cost of the glass spheres per gallon of paint is reported as low as 64 cents when used at the rate of 4 lb. per gallon up to $1.62 when used at the rate of 6 lb. per gallon. It is now generally known that beads may be purchased m carload lots for as little as 12 cents per pound.

By reason of using a dashed rather than a solid line, a savmg varying from 50 to 80 percent is reported. States using a 20 f t . paint line with a 20 f t . gap or any pattern using the same length paint line and gap between, accomplish a 50 percent saving in paint. Three states reported usmg a 15 to 35 f t . pattern with a saving of 70 percent and one state saves 80 percent usmg a 10 to 40 f t . marking.

COST OF VARIOUS PAINTS

Information regarding purchase cost and application cost of plain paint, asphalt paint, reflectorized white and r^lectorized yellow paints was in­sufficient on a number of the returned questionnaires and i t is therefore impracticable to arrive at any definite comparisons. Some states furnished the name of the manufacturer, others stated that the paint is purchased on bid while the paint for one state is manu­factured at the State Prison.

Factors entering into the cost of paint include quality, freight rate, and whether or not the purchase is made on a competitive basis. Currently i t I S reported that plam white paint is purchased for as low as $1.19 per

6

gallon and as high as $3.00 per gallon. The average cost per gallon from 36 states reporting is $1. 69 per gallon.

Analysis of the information on the returned questionnaires indicates that while some states reported total cost per mile on the basis of using a dashed line, others reported on the basis of using a single solid line. For this reason, we are unable to furnish a comparison of cost per mile figures. However, al l information obtained has been indicated on the tabulation chart and may be studied by the individ­ual for detailed costs in any particular state. It is reasonably safe to assume that any figure indicating under 9 gallons of paint used per mile is for a dashed line and any figure over 12 refers to the single solid line. The cost as reported varies between $13.00 and $63. 00 per mile for a plain unreflec-torized marking. Application methods are largely responsible for this variance as between 5 and 100 miles of pavement are reported to be painted a day.

Fifteen gallons al paint per mile for a solid line 4 in. in width and 6 gallons per mile for a 15 f t . dash with a 25 f t . gap line are' practical to use for esti­mating purposes.

Ten states furnished limited infor­mation on the use of asphaltic type of paint. The cost varies between 17 cents and 46 cents per gallon for purchased pamt. One state reports a cost of $1.00 per gallon for asphaltic pamt.

Thirty-two states furnished current prices on reflectorized white paint, the low bemg $1. 94 - the high $4. 50 per gallon. The average cost per gallon is indicated at $3.14. As high as 23 gallons per mile and as low as 12 gallons per mile is reported as being used. It is assumed that these figures are based on a single solid Ime.

In nearly a l l states the additional cost of providing a reflectorized mark­ing may be attributed to the increase m the cost of the pamting material, as cost of application is practically the same in either case.

Twenty-three states furnished l imi t ­ed information regarding reflectorized

yellow paint. From 16 states using both white and yellow reflectorized pamt, i t is found that the average cost of white is $3.28 and the average cost of yellow is $3. 47 per gallon. This is an increase of 19 cents per gallon or 5. 8 percent when using yellow reflec­torized pamt.

REPORTS FROM OUTSIDE THE UNITED STATES

III addition to receiving completed questionnaires from all 48 states, replies were received from the prov­inces of British Columbia, Manitoba, Nova Scotia, Ontario and New Bruns­wick in Canada and the Territory of Hawaii. Two of the provmces contract for the placing of their markings, two use commercially manufactured equip­ment and one has constructed its own striper. Hawaii uses a purchased unit.

The length of the paint cycle in the Canadian Provinces is reported as varying between 30 and 120 f t . The length of the dash line varies from 10 to 20 f t . with a 20 to 100 f t . gap. Three place a 4 m. width marking, one a 4-1/2 in. and one a 5 in. width. Hawaii places a 6 f t . dash Ime with a 9 f t . gap, using a 4 m. width line.

SUMMARY

The foregoing information is based purely on the data reported by the respective states and'^rovinces. The information has been tabulated by states alphabetically m the charts, ¥^ich are folded in at the end of this buUetm.

It is the thought of the Committee that the results of this project should prove of value to the several states in securmg g r e a t e r effectiveness and economy in pavement marking methods and procedures; also that this report together with future studies wi l l con­tribute greatly toward establishing greater uniformity in marking prac­tices, ultimately leading to the evolu­tion of a form of markings which wil l be best from a stanc^oint of safety as well as from other points of view.

PRESENT PREFERENCES FOR TRAFFIC PAINT G. W. Ashman, Research Department,

The New Jersey Zinc Company, Palmerton, Pennsylvania

SYNOPSIS

The results of a survey on traffic paint that was completed during the fall of 1950 are discussed in this paper.

Replies to questionnaires were received from 34 states that are well distributed geographically, and from 175 manufacturers of traffic paint that are representative of varying degrees of importance in all parts of the country. Compilation of the results of this very generous response affords an up-to-date and representative canvass of opimons and preferences eiqpressed both by the consumers of traffic paints and by the manufac­turers of the product

Estimated quantities of white and yellow road marking paints used in 1949 and 1950 by 33 states mdicate that about 11 percent more whites and about 9 percent more yellows were used m 1950. The ratio of white to yellow was about 7 to 3 for both years.

A great increase m the use of retro-reflective road markings is indicated by the returns The reported estimated consumptions for 1949 and 1950 indicate that 67 percent more beaded whites and 59 percent more beaded yellows will be used in 1950 than m the previous year.

In types of opaque white pigments preferred, both the states and the manufacturers rate titanium pigments first, followed by zinc oxide and lithopone. Among the extender pigments, magnesium silicate has first preference, definitely.

Preferences on vehicle types selected indicated no significant change between the types used in 1949 and in 1950. About half of both groups reporting mdicated a preference for the alKyd resm types, and about a third of both groups reported a preference for the phenolic resin varnish types. The phenolic varnish- dispersion resm type was voted as third in importance, being somewhat more popular among the states than among the manufacturers.

Both the highway departments and the traffic paint producers indicated the relative importance of those pamt properties that will receive greater emphasis durmg the coming year. A summation of these preferences, both on a first-choice basis and on a weighted basis, mdicates that both groups have voted "Improved Service Life" as defmitely first m importance. There was decidedly less unanimity of opinion on the relative importance of the other properties Apparently, the highway departments desire better visibility and better film properties and do not stress "Cost lier Gallon", while the manufacturers are emphasizmg improved liquid paint and application properties while rating "Cost per Gallon" as quite important.

Those dealing extensively with traffic zone marking paints are aware of the widely varying and sometimes contra­dictory characteristics of these mate­rials. They may not be as completely informed, however, on the detailed balancing and adjusting necessary in formulating the desired types of paints. The major difficulties involved are the cost and availability of the ingredients, and the preferences expressed or implied for the storage properties, liquid paint properties, application properties, and service properties of the product. To attain some of these requirements i t may be necessary at

times to sacrifice other desirable characteristics. To attempt to deter­mine what type of formula is most suitable for a given consumer, one must f i r s t know 'wtiai properties or qualities are of major importance to that consumer and which ones are of minor importance. Solution of this complexity is further complicated by changes in preferences, service re­quirements and money available for the project.

To obtain information on those preferences most widely held at this time, our Company has made a survey on the subject. Compilations of the

8

results of this survey are presented in this paper. Collations of the prefer­ences indicated by current procedures are discussed f i rs t . The comparisons of the relative choices indicated by answers to identical questions by the highway departments and by the manu­facturers of traffic paint then follow. Formulations sheets are appended for one white and two yellow paints that appear to satisfy a large number of the requirements and preferences reported.

Questionnaires on traffic zone mark­ing paints were sent to state highway departments and to paint manufacturers during the summer of 1950. The high­way departments were selected as the largest group of consumers of road marking paints, and the questionnaire that they received was designed to indicate their requirenients and prefer­ences. The questionnaire sent to the pamt manufacturers was designed to obtain the opiuons and preferences of the traffic paint producers. In both forms, however, there were identical ^ lists of questions about preferred paint compositions and paint service prop­erties. B o t h questionnaires were arranged for ease and convenience of reply, and a number of questions that might have been of general interest were omitted for brevity. Copies of the t*fo types of forms are appended.

Knowing that the New Jersey Zinc Company does not produce paints, you may ask why we conducted a survey on the types of traffic paints preferred. The answer I S that our pigment products are used m all types of paints, with considerable tonnages being used m white and colored traffic paints. To secure information on the most effective use of these pigments, regardless of the type of vehicle used or the service conditions, our laboratory has con­ducted continumg investigations on the subject for almost thirty years. Some of these investigations have been quite comprehensive, and both the manufac­turers and the highway departments have cooperated m making service tests on the traffic paints. Without identify-mg the cooperators, i t has been a consistent policy of our Company to re­port the results obtained to all of those

Interested. Indeed, the idea of the 1950 survey originated during a consid­eration of the most effective methods for using the information obtained from more than two hundred road service tests made in 1949. Each questionnaire was accompanied by a brief summary of the 1949 test results, a copy of which is appended.

The state highway d^artments, with their paint testing laboratories, trained personnel, and experienced background in specific properties needed for road marking paints in their areas, can set up standard requirements for traffic paints. Also, they can purchase these specific formulas in sufficient volume to assure the economical production of the desired types. Other users of traffic paints, namely the counties, municipalities, i n d u s t r y , railroad, airports, etc., seldom have the fac i l ­ities, personnel and eiq>erience neces­sary for setting up specific traffic paint requirements. Even if these specifica­tions are set up, the individual purchase orders may not be large enough to justify their special preparation without a price premium. Consequently, these groups of consumers usually rely on the competence,- ejq^ierience and integ­rity of the paint manufacturer to obtain the best paint for their needs.

The response to the questionnaires was very generous and the ratio of returns was surprisingly large for this type of survey, due probably to the widespread interest in new types of paints, the increased^ use of glass beads, and the possible necessity for considering substitute materials in the near future. Replies were received from 34 states that are well distributed geographically and from 175 manufac­turers of traffic pamts who are repre­sentative of varying degrees of impor­tance in all parts of the country. We wish to express our sincere appreciation to all of those who participated.

Thirty-four state highway depart­ments replied to questions on the "Highway Department" form, but some did not answer each group of questions. Therefore, some of the compilations discussed below represent a fewer number of states.

9

Estimates on the gallons of white and yellow traffic paints used in 1949 and 1950 were reported by 33 states. The respective totals for the retro-reflective type paints were also report­ed. Summations of these reported totals, together with reported data on black marking paint, are given m Table 1.

TABLE 1

ESnHAITO GALLONS OF ROAD MARKING PAINTS USED IN 19S0 AND 1949. 33 STATES REPORnNG

1950 1949

White 580,025 677,290 White > i t h Beads 519,080 310,034

Total White 1,099,105 987,324

Yellow 178,805 250,430 Yellow wi th Beads 298,100 ' 187,865

Total Yellow 467,905 438,295

Grsnd Total 1,576,010 1,425,619

Ratio of White to Yellow 70 to 30 69 to 31

Black 104,650* 143,500

'Four s ts tes repor t i ag This represents sbout 11 percent increese oTer the t o t a l f o r these states in 1949 A f i f t h state repor t ing fo r 1949 w i l l not spply black in 1950

The estimated t o t a l s f o r white and yel low paints used i n 1949 and 1950 sre represented i n Figure 1 together w i t h the es t ins ted t o t a l of white and yellow paint used i n 1948 by the sane 33 states

Based on 1948 data reported by Waters^ for these states, the 1950 total for white and yellow traffic paints is about 16 percent higher than the 1948 total. The total 1948 usage of white, yellow and black reported by Waters (for 44 states only) is in excess of 1,893,000 gallons. Assuming a 16 percent average increase from 1948 to 1950 for these 44 states, their estimat­ed total usage m 1950 would be more than 2,202,000 gallons. It is probable, therefore, that the 1950 total usage (tf road marking paints for all states might be about 2-1/2 million gallons. '"Progress Report of Comments on Roadway Pavements Markings", by C. R. Waters, Highway Research Abstracts, July 1949.

The proportions of the various types of paints used in 1949 and 1950 and the percentage changes in 1950 for the estimated pamt quantities listed m Table 1 are shown m Table 2.

It wi l l be noted that the ratios for the states completing this portion of the questionnaire show that for the white traffic paints the beaded applica­tions represented about one-third of the total m 1949 and about one-half of the total in 1950. In the yellow traffic pamts, the use of beaded markmg lines increased from about two-fifths of the total in 1949 to about three-fifths of the total in 1950. During both of these years the ratio of all whites to all yellows was about 7 to 3.

TABLE 2

RATIOS OF WHITE AND YELLOW TRAFFIC PAINTS USED IN 1950 AND 1949, 33 STAINS REPORTING

Change 1950 1949 in 1950

Percent Percent Percent

White 53 69 - 14 White with Beads 47 31 + 67

Total White 100 100 + 11

Yellow 38 57 • 29 Yellow wi th Beads 62 43 + 59

Total Yellow 100 100 + 9

The right hand column of Table 2 shows mcreases from 1949 to 1950 of 67 percent for the white beaded mark­ings and of 59 percent for the yellow beaded markings. These very large rates of change serve to emphasize the rapidly increasing and widespread adoption of glass beads in traffic paints. This conversion to the beaded type road markings was accompanied by a mod­erate mcrease in the total amount of traffic paint used. The increase m quantity of white paints used in 1950 versus 1949 amounted to about 11 percent, that of the yellow pamts to about 9 percent, while the combined increase for both types was slightly less than 11 percent.

Table 3 summarized the replies given by 34 states regarding the basis of traffic paint purchases by their depart-

10

ment. Twelve of the states indicated that a single major requirement was used, and none of these cited cost per gallon as the requirement. Thirteen states mdicated that two requirements were used, and nme of these cited cost per gallon as one requirement. Nme states reported that three or more requirements were used, with six in­dicating that cost per gallon was one of the bases of purchase.

trend towards the use of glass beads regardless of the significant increase in f i r s t cost.

Questions on the relative road service life obtamed with the various types of paint were answered by 34 states. Most of those pomted out that their estimates were for average serv­ice under average conditions, since the type of road, traffic concentration, f i lm thickness, and many other factors

TABLE 3

BASIS OF 1HAFFIC PAINT PURCHASE IN 19SO, 34 STATES BEPORTING

Basis of Purehsss

Speeif icst ion Conpoaition Performance

Cost per Gsllon

Other

Number of States

Number of Requirements per State Single Double Mul t ip le

4 2 6

None

None

12

8 7 2

9

None

13

Total Votes

A l l States

20 14 14

15

2

34

TABLE 4 TABLE 5

MONTHS ESTIMATED ROAD SERVICE LIFE 34 STATES REPORHNG

Type of Stripe

White Paint White with Beads Yellow Psint Yellow with Beads

Average ATerage Normal Optimum SerTice Service Range*

13 14 12 14

4 to 20 6 to 20 5 to 18 3 to 20

*TWo of the 34 states indicated a possible l i f e of 24 months and one a possible l i f e of 36 months These estimstes sre not included i n the rsnges l i s t e d

Considering the total votes listed in Table 3, purchase of paint by specifica­tion, either general or composition, or combined with performance, is the most general procedure in 20 of the 34 states. Of the 14 other states replying, two purchase solely on a composition basis and six purchase solely on a per­formance basis. According to these results, the survey indicates that purchase on a cost per gallon basis is of minor importance in most of the states. This is consistent with the enthusiastic

EFFECT OF BEADS ON FILM LITt OBTAINED

Shorter L i f e Ssme ATerage Longer L i f e for Beaded L i f e fo r for Beaded

Painta Beaded and Painta (States) Non-Beaded (Ststes)

Psints (States)

Whites Only Whites and Yellows 1 Yellowa Only

Total Statea 1

2 7 1

10

4 6 1

U

might cause significant variations in service obtained. The replies received are summarized in Table 4. These results mdicate that average non-beaded applications may be serviceable for about six months, while the beaded paints are serviceable for slightly longer periods.

An analysis of the specific replies as to the effect of glass beads on the service life of the films is tabulated in Table 5 according to the effects report­ed for white and yellow pamts.

The Table 5 results confirm in part the averages reported in Table 4 but indicate that the Table 4 data are not

11

consistently applicable. The differ­ences of opinions listed in Table 5 probably result from the effects of formulation and service variables. They also probably in±cate the possi­bility of obtaining misleading indications in a too-brief summary of the variety

white and yellow paints applied without beads. These comparisons are listed in Table 6.

These opinions indicate that the color of the traffic paints did not con­sistently affect the service of the films. Six of the other states reportmg use

ESTIMATED GALLONS PAINT USED ^NHVAt . T^TAt , ; Tm STATES HEPOTTi^

GALLONS M I N T

I HILLION-

• • . •

.• • • » « .

TOTHL rELLOU

TOtU. WHITES

1948 1949 1950 Figure 1

TABLE 6 TABLE 7

RELATIVE FILM LIFE OF NGN-BEADED WHITE AND YELLOW PAINTS

Same Average F i l m L i f e White and Y e l l o w Non-Beaded P a i n t a 14 S t a t e s

Longer Average F i l m L i f e f o r White P a i n t S t r i p e s 2 S ta t e s

Longer Average F i l m L i f e f o r Y e l l o w P a i n t S t r i p e a 3 S t a t e s

of estimates condensed for the Table 4 values. The net result of the Table 5 summation is to indicate that beads affected a shorter film life in one state, had no significant effect m ten states, and effected longer film life m 11 states. Four of the other states re­porting indicated no comparisons of film life, three did not use beads, and five- used beaded paints only.

The estimates given by the individual states on film life also offered compar­isons of the relative service periods of

TYPE OF nUFnC PAINT MADE DURING 1949

C o l o r o f P roduc t

Whi te

Whi te w i t h Beada Y e l l o w Y e l l o w w i t h Beads Other

Produced Whi te P a i n t Only Produced No Whi te P a i n t Produced Whi te and Y e l l o w Only Produced Other C o l o r s (Green,

Red, Orenge, B l a c k )

'Some o f those r e p l y i n g d i d n o t i n d i c o t e which c o l o r s were produced

white paint only, three use yellow paint only, and three did not indicate the color of the paint used. Three of the

R a t i o o f Number o f T o t s l Msnufsc- R e p l i e s

t u r e r s Percen t

173 99+ 40 23

I4S 83 32 18 5 7 ' 33

24 14 2 I

115 66 3 4 ' 20

12

SIX using white paint use only beaded paints.

Table 7 summarized the replies received from several hundred paint manufacturers of whom 175 reported that they produce road marking paints. With some, this is a major part of their business. With others, it is of relatively minor importance even though the quantity produced may exceed that of a smaller company engaged mainly in traffic pamt production. Data given in this paper, however, do not consider the relative quantities pro­duced by the individual companies.

markings, and a summation of these results IS given in Table 8. While it may appear that the highway depart­ments might have more complete in­formation on the relative effects of the several variables, they are probably no more mterested than the manufac­turers. Indeed, much of the business obtained by the manufacturers might depend upon their proper evaluation of the various factors. Their replies were listed according to first choice, second, third, etc. The total weighted votes for each item, listed in the middle column in Table 8, were determined and

TABLE 8

PAINT MANUFACTURERS' OPINICNS ON THE RELATIVE IMPORTANCE OF VARIOUS FACTORS TO THE SERVICE LIFE OF THE FIIM

T o t a l R e l s t i v e Number o f Weighted Order o f

Fac to r s C i t e d F i r s t Choices Votes* P re f e r ence

Type o f V e h i c l e 108 744 1s t

F i l n Th ickness 18 360 2nd A p p l i c a t i o n V a r i a b l e s 16 327 3 rd Type o f Pavement Sur face IS 296 4 t h Type o f H i d i n g Pigment 4 250 5 t h Type o f Extender Pigment 1 229 eth

"Where f i v e cho ice s were i n d i c a t e d , the f i r s t cho ice wBB we igh t ed as f i v e v o t e a , the aecond aa f o u r , e t c H ie t o t s l s g i v e n i n t h i s column r e p r e s e n t the r e s u l t i n g sums f o r t he r e s p e c t i v e I tems

Almost all of the 175 traffic paint manufacturers reported that they produce white marking paints; 83 percent reported the production of yellow traffic paints; 66 percent re­ported the production of whites and yellows only; and 33 percent reported the production of other colors, such as green, red, orange or black. Only 23 percent of the companies produce beaded white paints, and only ISpercent produce beaded yellows. This might mdicate that the highvray departments had taken the initiative on ejq ianding the use of beaded paints, or it might indicate that they preferred to add the beads at the time of paint application rather than purchase paints containing glass beads.

The paint manufacturers were asked to list their opinions on the relative importance of half a dozen factors influencing the service life of the road

these values were found to agree in relative order with the order of prefer­ence indicated by totals of the first choices.

Of the 163 manufacturers replying to this section of the questionnaire, more than half selected the type of vehicle as being the most important factor in service life of the film. There was much less agreement as to the second most important factor but it was gen­erally agreed that film thickness, ^plication variables, and type of pavement surface were all fairly im­portant factors.

The relatively low position of im­portance assigned to the effects of the hiding pigments on service life is somewhat surprising. There have been occasions when our customers have ej^ressed contrary opinions about the effects of some of the hiding pigments.

13

The results summarized in Table 9 represent the replies received from the states and the manufacturers re­garding the pigments used. The ques­tionnaire sent to the highway depart­ments asked for an mdication of the opaque and extender pigments preferred in white 'traffic paints, beaded and

the opaque pigment when beads are used, and two change the extender pigments when beads are used. The percentages mdicated m the left-hand column in Table 9 are for the non-beaded paints but the replies regarding the use of beads did not materially change the ratios and, therefore, are not indicated

TABLE 9

WHITC PIGMENTS PREFERRED BY HIOiWAY DEPAR1MENTS AND BY PAINT PRODUCERS

White Opaque Pigments

T i t a n i u m D i o x i d e T i t a n i u m - C a l c i u m Z inc Oxide L i thopone

Extender Pigments

Magnesium S i l i c a t e Diatomaceous E a r t h W h i t i n g Pumice Other (Ex tenders On ly )

Frequency o f Choice ( S t a t e s ) Pe rcen t

50 44 29 18

56 15 18 18 18

Frequency o f Choice ( M a n u f s c t u r e r a )

No Beads Percent

61 59 49 35

80 39 33 21 13

Beaded Pe rcen t

71 55 55 13

90 47 29

' 8 16

Arerage Order o f P r e f e r ence

1st 2nd 3rd 4 t h

1s t 2nd 3 rd 4 t h Sth

non-beaded types. The paint manu­facturers' questionnaire contained a similar list of questions but they were asked to indicate those pigments that were used in substantial percentages in traffic paints made by their company in 1949. Thirty-four states and 175 producers of traffic paint replied, and the frequencies, of preferences are indicated in Table 9. It will be noted that the respective percentages for each group total more than 100 percent, signifying the use of more than one pigment in the formula.

Three of the states replying used only yellow marking paints in 1949 and 1950. Of the 31 states using white paints, five indicated no preference in the opaque pigments or in the extender pigments used. Considering the differ­ences indicated between the non-beaded and the beaded paint formulas, three of the states reported that they used only beaded paints, 25 reported that the same pigment combinations are used both with and without beads, four change

FREQENCY OF CHOCE-WHITE OHMXJE PIGMENTS VSED IN NON-BEADED Tt^AFFIC pMNTg

OTHER

STATES MANUFACTURERS

Figure 2

in the table. As the Table 9 results indicate, the

titanium pigments have first preference, followed by zmc oxide and lithopone, both among the traffic paint manufac­turers and among the highway depart­ments. In the non-beaded paints, the manufacturers seem to be more cog­nizant of the advantages of zinc oxide

14

than are the states, and they further increase the use of this reinforcing pigment for the beaded formulas. More changes are made also in other pig­ments used by the manufacturers when formulating for the retro-reflective road markings than are made by the states when beads are used. The increased use of titanium dioxide and of zinc oxide by the manufacturers when formulatmg for beaded paints is evidence that cost is not the most im­portant factor in designing the formula.

Figure 2 represents the relative fre­quencies of choices for white opaque pig­ments used m non-beaded traffic paints by the states and by the manufacturers.

paint manufacturers than by states, but the frequency of use decreased slightly in the beaded formulas. "Other" types of extender pigments used included aluminum silicate, mica and various forms of barium sulfate. There is evidence that both the state highway departments and the traffic paint manu­facturers are giving mcreasing attention to the use of barium sulfate m road marking paints.

Considering preferences for types of vehicles, 28 states voting on the types found to be most satisfactory and 175 traffic pamt manufacturers votmg on the types used by their companies in 1949 have indicated their respective

TABLE 10

PREFERENCES INDICATED FOR V F H i a E TYPES BY HIGHWAY DEPARTMENTS AND BY PAINT MANUFACTURERS

Frequency o f Choice ( S t a t e s )

f^requency o f Choice ( M a n u f a c t u r e r s )

No Beads Beaded Average Order o f P r e f e r ence

\ Percen t Percent Percen t

V e h i c l e Type

A l k y d Reaina 54 52 62 1s t

PhenolICS 29 34 32 2nd P h e n o l i c - D i s p e r s i o n 21 10 19 3rd

Res in Copolyiner-(3i l o r m a t e d U 9 11 4 t h

P s r a f f i n Es t e r (Sum 0 18 13 4 t h N a t u r a l (lums 7 14 5 6 t h Oimsr ( f o r Y e l l o w s ) 3 4 - -S t y r e n e t e d O i l s 0 2 - -Other ( A l l Types) ' 21 14 11 ,-

Considering the extender pigments, both the states and the manufacturers indicated a definite preference for magnesium silicate. The ratios of use by the states in non-beaded paints and in the beaded types were so similar that data for the beaded paint formulas are not given in Table 9. A considerably larger proportion of the traffic paint manufacturers indicated the use of magnesium silicate, both in the non-beaded and in the beaded paints. The manufacturers, however, also used other types cl extenders more fre­quently, with the diatomaceous earth being the most favored. Whiting was also more generally used by traffic

choices. The frequency of choice for each vehicle type is listed m Table 10, data for the state highway department preferences being listed for the non-beaded paints and data for the manu­facturers preferences being listed both for non-beaded and for beaded paints. Frequency of choice values for beaded paint vehicles preferred by the states are not listed in Table 10 because they are so similar to the values for the non-beaded types.

The relative orders of choice for the types of vehicles preferred in traffic markmg paints place the alkyd resin type as definitely first choice by both groups reporting. Phenolic resin

15

varnish types are the second choice of both groups, and the phenolic-disper­sion resin type is rated third in fre­quency of preference. No data are available on the total quantities of the respective types of vehicles that are used annually.

In the category of "other" vehicle types, the state highway departments reported the acceptance of pentaery-thritol ester resins, chlorinated rub­ber, phenolic modified pentaerythritol, maleic modified phenolic, zmc resinate, and tung oil varnishes. Under the same classification, the manufacturers listed most of the types cited by the states.

and the report by one state that a dif­ferent type vehicle was specified where glass beads are used than is specified for the non-beaded paints. Six states indicated no preferences as to the type of vehicle specified for their white and yellow road marking paints. No sig­nificant changes in types of vehicles used in 1949 versus 1950 were indicated m the preferences reported.

Of all the results indicated in this survey, perhaps the most interesting phases were those expressmgthe trends in opmions and preferences, as shown in Table 11. Some of these have been enumerated in the results previously

FREQUENCY OF CHOICE- TYPES OF V E H I C L E S

USED IN NON-BEADED TRAFFIC RMNTS

PHENOLICS

STATES MANUFACTURERS

Figure 3

Comparisons of the relative fre­quencies of choice by the states and by the manufacturers for types of vehicles used m non-beaded traffic pamts are shown in Figure 3.

Pertment details that may be of interest to the highway departments include the report by 16 states that the same types of vehicles are pur­chased for non-beaded and beaded marking paints, the report by three states that they apply beaded markmg lines only, the report by two states that bead-containing paints are purchased for their retro-reflective markmgs.

discussed and some have been indicated by Inference. Table 11 summarizes the replies received from identical lists of questions in both the state highway and the "producer" forms. The wording m the questionnaire was: "To aid us in the following trends, indicate on which properties. you intend to place greater emphasis in the coming year . . . " Eight options were listed and it was requested that at least three of these, but not more than five, be numbered m order of importance.

The response received from both groups was most gratifying. Space does

16

not permit detailed analysis of the preferences reported but the orders of preference indicated in Table 11 are believed to be a fair presentation of the consensus. Comparisons of the choices mdicated by some of the highway engi­neers with the traffic paint specifica­tions for their respective states would indicate that revision or e:q>ansion of some of the specifications was badly needed. The results indicated that both for the state highway departments and for the traffic paint manufacturers the thinking regarding future trends was considerably in advance of present practice. Both groups are to be con­gratulated on their alertness to future possibilities m road marking paints.

Considering the mdividual returns, 34 state highway departments and 162 traffic paint manufacturers replied to this list of questions. For the states, 30 indicated their first, second, etc., choices. For the manufacturers, 148 indicated their choices in descending order of importance. A summation of the preferences on a weightecP basis agrees with the order of decreasing preferences that is mdicated by the respective first-choice totals, both for the highway department replies and for the manufacturers replies.

In the individual replies, "Improved Service Life" was defmitely the first choice of both groups for greater emphasis during the coming year. The relative ratings on "Rate of Dry" and "Storage Stability" were also in fairly good agreement, but the unanimity

'where f ive choices were indicated, the f i r s t choice was rated as f ive votes, the second four votes, etc. The resulting sums f o r each I t e m determmed the orders of preference l is ted in Table 11.

agreement on the importance of the other properties was less pronounced m the two groups. In general, the Table 11 comparisons probably indicate the concern on the part of the consumers for better service properties of the film without stress on the paint cost, and the concern on the part of the manufacturers for better liquid paint

TABLE 11

RELAnVE ORDER OF PREFERENCE FOR FintJRE EMPHASIS CN PAINT PROPERTIES

P a i n t P r o p e r t i e s

Improved S e r v i c e L i f e N i g h t V i s i b i l i t y Rate o f Dry Storage S t a b i l i t y Day V i s i b i l i t y Cost per G a l l o n B l e e d i n g Res i s tance Other

S t a t e Highway T r a f f i c P a i n t Departments M a n u f a c t u r e r s

1s t 2nd 3rd 4 t h 4 t h 6 t h 6 t h

N e g l i g i b l e

1st 6 t h 2nd 4 t h 7 t h 3 rd 4 t h

N e g l i g i b l e

and application properties at competi­tive costs. The de-emphasis of cost by the highway departments is a logical reaction to the great increase in uterest in retro-reflective road markings, and it is probably coupled with their desire to keep such films on the road as long as IS practical.

In conclusion, I again wish to express our deepest gratitude to all of those who participated m the survey, and to your committee who made this presentation of preferences possible. Limitations of space prevented comment on many of the details reported but these will be freely available to those mterested, with the exception that the identity cl those organizations making the com­ments manifestly cannot be revealed.

17

APPENDIX A Traffic Paint Formula T-4418-TAEI - White Traffic Paint Formula T-5418-MEAI - Yellow Traffic Pamt Formula T-1451-MEAI - Yellow

TRAFFIC PAINT FORMULA T-4418-TAEI

Formula Representative ' Percent Formula

Pigment - 57-59 Percent

Titanium Dioxide (1) 10 74 lb. Lithopone (2) 40 295 lb. ZmcOxide{3) 10 74 1b. Pumice (4) 10 74 lb. Magnesium Silicate (5) 29 214 1b. Alummum Stearate 1 7 lb .

Vehicle - 43-41 Percent

Alkyd Resm Solution (6) 65.6 44-7/8 gal. V . M . and P. Naphtha 33.3 29 gal. Lead Dr ie r (24 % Pb) 0.9 5 p t Cobalt Dr ie r (6 % Co) 0.2 1 pt.

Yield 100 gal. Non-volatile m Vehicle 40 Percent Weight per Gallon 12.7 lb. P. F . V 52 Percent

(1) Rutile or anatase type may be used. Rutile provides better durabibty; anatase, better color and cleansing.

(2) Albalith-351 (high consistency) or Albalith-73 (lower consistency). (3) X X - 2 , XX-50, XX-55, XX-503 or XX-601. (4) Should be added after paint is ground. Where application is by spray gun, use No. 0-1/2, 1/2

or 0-3/4. When application equipment permits the coarser pumice, No. 1 or 1-1/2 may be used. If glass beads are to be used, the pumice may be omitted.

(5) Medium consistency f ibrous type. (6) Glyptal 2475 (60 percent non-volatile) o r any recommended alkyd that is compatible with zinc

oxide may be used. If non-volatile is not 60 percent, adjustment should be made in quantity of alkyd and V. M . and P. Naphtha. I f paint is to be applied under unfavorable conditions or more rapid drying is desired, a V. M . and P. N^htha-a lkyd solution should be used ustead of a mmeral spir i ts-alkyd solution.

The properties and cost of the paint may be varied by changing the composition of the pigment,' the vehicle, or the proportions used.

Increasing the T1O2 or zmc oxide content mthe pigment increases the length of service obtamed. High zinc oxide content is especially desirable when the paint is to be glass beaded. Substitution of water-ground mica f o r part of the magnesium silicate also mcreases the durability of the f i l m . Replacing part of the lithopone l>y additional magnesium silicate lowers cost at a sacrif ice in the service obtained; also replacement on an equal weight basis of the pumic and magnesium silicate by an me^qiensive ground whitmg lowers cost at a sacrif ice in durability.

The use of high viscosity resins or high consistency pigments, which permit an increase in the vehicle content or volatile content in the vehicle, reduces cost, although generally accompanied by a decrease in service. Increasing the non-volatile vehicle usually results in improved service.

Note: The information contamed herein is f r o m sources which we believe to be reliable and is intended to offer helpful suggestions. We do not, however, guarantee the results to be obtamed f r o m Its use.

18

TRAFFIC PAINT FORMULA T-5418-MEAI

Formula Representative Percent Formula

Pigment - 58 - 60 Percent

C P . Chrome Yellow 40 3181b. Zinc Oxide (1) 15 119 1b. Lithopone (2) 15 119 lb . Magnesium Silicate (3) 29 230 lb. Aluminum Stearate 1 8 lb .

Vehicle - 42-40 Percent

Alkyd Resm Solution (4) 65.6 46-1/2 gal. V . M . and P. Naphtha 33.3 30 gal. Lead D r i e r (24 % Pb) 0.9 4 qt. Cobalt Dr ie r (6 % Co) 0.2 1 pt.

Yield 100 gal. Non-volatile in Vehicle 40 Percent Weight per Gallon 13. 5 lb. P. F . V 48.9 Percent

(1) X X - 2 , XX-SO, XX-55, XX-503 or XX-601. (2) Albalith-351 (high consistency) or Albalith-73 (lower consistency). (3) Medium consistency fibrous type. (4) Glyptal 2475 (60 percent non-volatile) or any recommended alkyd that is conq)atible with zinc

oxide may be used. If non-volatile is not 60 percent, adjustment should be made i n quantity of alkyd and V. M . and P. Naphtha. I f paint is to be applied under unfavorable conditions or more rapid drying is desired, a V. M . and P. Naphtha-alkyd solution should be used instead of a mineral spir i ts-alkyd solution.

The properties and cost of the paint may be varied by changing the composition of the pigment, the vehicle, or the proportions used.

The chrome yellow is the most expensive pigment constituent, especially on a volume basis. Pigmentations containing combinations of C P. lead chromate, z u c oxide, lithopone and magne­sium silicate provide more durable paints than those containing 0« P. chrome yellow alone or in combination with merts A l l indications are that both zinc oxide and lithopone improve the dur­ability of the paint and the l i m i t on their substitution f o r chrome yellow is the inclusion of s u f f i ­cient chrome yellow to assure the desired yellow color. High z u c oxide content i s especially desirable i f the paint is to be beaded. Replacement of a portion of the magnesium silicate 1^ water-ground mica or l>y pumice improves the durability of the f i l m .

Increasing the non-volatile content of the vehicle usually improves durabili ty, while the use of high viscosity resmsor high consistency pigments, which permit an increase in the vehicle content or an wcrease in the volatile content of the vehicle, reduces cost but usually with a sacrifice in the service obtained f r o m the paint.

Note: The information contained herein is f r o m sources which we believe to be reliable and i s intended to of fer helpful suggestions. We do not, however, guarantee the results to be obtained f r o m i ts use.

19

TRAFFIC PAINT FORMULA T-1451-MEAI

Formula Percent

Representative Formula

Pigment - 53-55 Percent

C P . Chrome Yellow* 40 265 1b. Zinc Oxide (1) 15 100 lb. Lithopone (2) 15 100 lb. Magnesium SiUcate (3) 20 192 lb. A lumuum Stearate 1 7 lb.

Vehicle - 47-45 Percent

Varnish (4) 43 33-3/4 gal. Dispersion Resui (5) 28. 7 21-3/4 gal. Butanol 4.5 3-3/4 gal. V . M . and P. Naphtha 23.3 21-1/2 gaL Lead Dr ie r (24 % Pb) 0.31 1-1/2 pt. Cobalt Dr ie r (6 % Co) 0.13 3/4 pt. Manganese Dr ie r (6 % Mn) 0.06 3/8 p t •

Yield 100 gal. Non-volatile m Vehicle 37 Percent Weight per Gallon 12-1/4 lb. P. F. V 41 Percent

*The chrome yellow is the most eicpensive pigment constituent, especially on a volume basis. Pigmentations containing combinations of C P . chrome yellow, zmc oxide, lithopone and magnesium silicate provide more durable paints than those contaming C. P. chrome yellow alone or in combination with inerts. A l l indications are that both zinc oxide and lithopone improve the durability of the paint and the b m i t on their substitution fo r chrome yellow I S the inclusion of sufficient chrome yellow to assure the desired yellow color. High zmc oxide content is especially desirable if the pamt is to be beaded.

(1) X X - 2 , XX-50, XX-55, XX-503 or XX-601. (2) Albalith-351 (high consistency) or Albalith-73 (lower consistency). (3) Medium consistency fibrous type. (4) 25-gallon 80 percent tung oil-20 percent Z-3 dehydrated castor o i l , modified phenolic resin

varnish. (Bakelite EF-1368 t ra f f i c pamt varnish or equal). VolatUe - 49 percent, Viscosity - B-C, Weight per Gallon - 7.18 lb . This varnish must be compatible with zmc oxide.

(5) Bakelite Dispersion Resm BK-16624 (50 percent K. V. O or equal).

Note: The information contained herem is f r o m sources whiCh we believe to be reliable and is mtended to offer helpful suggestions. We do not, however, guarantee the results to'be obtained f r o m its use

20

APPENDIX B t

Traffic Paint - Summary Submitted with each Questionnaire Questionnaire - Road Marking Traffic Pamts - Form Sent

to Highway Departments Questionnaire - Road Markmg Traffic Paints - Form Sent

to Pamt Manufacturers

TRAFFIC PAINT

For a number of years, we have conducted extensive mvestigations on t r a f f i c paint, both as laboratory studies and as f i e l d service tests. The laboratory work ucluded the preparation of varnishes f r o m conventional and f r o m new type ingredients, the makmg and testing of pamts contaming these varnishes, and the development of new test methods. Practical road tests have been made on a variety of road surfaces with varying t r a f f i c conditions. Also, cooperative road service tests have been run with paint laboratories and with highway departments in a number of states and cities. As a result, much information on pigments and vehicles has been developed and passed out to pamt manufacturers, highway departments, and others mterested.

In 1949, much more work was done. Pigment formulas previously found satisfactory in t r a f f i c paints were retested, vehicles that had been fo rmer ly accepted were rechecked, and new vehicles that had come before the public were put under test. Paints in both white and yellow were mvest i -gated and the performance of a number of beaded paints was observed. The road service tests were made on a concrete highway previously used f o r this purpose, a highway traversed daily by twelve to twenty thousand vehicles moving at high speed, with about one-third being heavy trucks. I t is the purpose of this paper to comment on this work to date. *

X In the earl ier work on the pigments, we found that pamts made with Albabth (lithopone) and Cryptone BT (titanated lithopone) gave excellent whiteness and necessary hiding power. The presence of zmc oxide improved performance. White water-ground mica extended the l i f e of the pamt. Pumice, either coarse or f ine , added 'measurably to the l i fe of the pamt, and the coarse grade, through adding roughness to the paint surface, greatly improved night v is ib i l i ty .

These conclusions were again substantiated in 1949. As a rule , anatase titamum dioxide pamts had better whiteness and appearance than the rut i le titanium dioxide or the calcium-base pigment paints, and were comparable in whiteness and v i s ib i l i ty to Cryptone BT or lithopone pamts. The calcium-titanium pigment formulas have consistently shown more d i r t collection, poorer color, and poorer durability. In the yellow pamts, when some of the chrome yellow was replaced by Albali th and/or zmc oxide, there was no degradation m color or durability - usually both were improved - and a reduction in cost was achieved.

The vehicles used m earl ier mvestigations together with those tested m 1949 represented every type of standard or alternate state highway department specification. These white and yellow pamts were formulated both with the specified pigmentations and with substitubons or modifica­tions In addition to the conventional type vehicles, several new types not m common use were mcluded m the tests. Brief comments on several different vehicles are given without attempting to l i s t the various pigment combmations found to be effective m each type.

Modified Phenolic Tung-Lmseed Vehicle (Federal Specification TT-P-115)

This vehicle is one of the oldest m point of use that has had popular acceptance by the trade. I t IS of the modified phenolic resm tung-lmseed o i l varnish type Our 1949 tests confirmed our former fmdmgs that, i f the varmsh is properly cooked, this vehicle gives pamts of satisfactory performance. In looking over the states now specifying this vehicle, we f ind that i t has lost some of I t s popularity to alkyds Good quality white or yellow pamts are equally durable m this vehicle.

Alkyd Vehicles

Our 1949 tests agam checked our previous work m mdicating that alkyds performed remarkably wel l . With these vehicles, fa i lure to dry to tack-free condition sometimes causes di f f icul ty , but I t I S not msurmountable. A survey of the use of this type vehicle shows that half of the states and many of the cities use i t m their standard or alternate specifications. I t i s equally good f o r whites or yellows.

21 TRAFFIC PAINT (Continued)

Manila Vehicles

The Manila gum type vehicle has been used quite extensively by some western states and has become identified as the "Califorma Vehicle". We again found i t s performance poor in our climate, significant fa i lu re developing in less than a month. Paints made f r o m i t seem to have lost favor in some states fo rmer ly specifying i t .

Bakelite Varnish-Dispersion Resin Vehicle

This IS a comparatively new-comer in the f i e l d and consists of a modified phenolic resin tung-Imseed o i l varmsh plus dispersion resm. I t has found favor in a few states. I t has the advantage of quick drying, which is much; to be desired, part icularly f o r city use. Our 1949 tests with i t were exploratory and did not permit drawing of f i n a l conclusions, but i t appeared that satisfactory service could be obtained with yellow pamts.

Goociyear Pliolite-Chlorowax Vehicle

Another of the newer type of vehicle is the combination of P l io l i t e , a copolymer of butadiene and styrene, and chlorinated paraff in. I t has been used in Texas and is finding some acceptance m other states. Paints made f r o m i t dried satisfactorily. Here agam the work was eiqiloratory and definite conclusions could not lie drawn, but yellow pamts appeared to give good service.

Hercules Pentalyn 802A-Parlon Vehicle

This IS probably the newest type t r a f f i c pamt to be advocated in a large way. So f a r , i t has gotten to the testing stage by states and cities. I t is a combmation of a Pentalyn 802A resm-tung o i l varnish and a Parlon solution, the latter being a solution of chlorinated natural rubber. Pamt made f r o m i t dries very fast and has aroused considerable mterest. So fa r as our work has gone, the paint performance looks interesting.

Yellow Pamts

Aside f r o m the differences in service properties of yellow pigmentations and white pigmenta­tions in certain types of t r a f f i c paint vehicles, probably the most mterestmg mdication of the 1949 tests was that the addition of either lithopone or zmc oxide to the yellow pamts effected significant reductions in cost without harming road service and frequently improvwg i t . These additions caused no noticeable degradation of the color, in fact , they effected better color retention and d i r t elimuiation. Several states now specify white pigment additions to yellow t ra f f i c paints. The economies effected by the addition of these white pigments are substantial.

Glass Beaded Pamts

The recent widespread mterest m glass beaded t ra f f i c stripes is of special mterest because i t focuses attention on the increased road service usually obtamed by adding zinc oxide to t r a f f i c pamt formulations. This improvement is evident m both the zmc sulfide and the titamum pigment pamts. In the past, i t has been of l i t t l e interest to highway departments to gam a few months added road service by the addition of the zinc oxide when such improvement would merely extend the service period mto the early wmter months. Now the added cost of glass beaded Imes makes an extension of the useful road service period very attractive, and extra cost that may be put mto the paint is of mmor importance m comparison with the improved service given. Although most of the vehicles tested with beads in 1949 and m previous years had good performance records, an important improvement is achieved i f the l i f e of the pamt itself i s extended, and i f the vehicle is strengthened to hold the imbedded beads longer. Some users are now asking f o r sixteen months' service, as compared with previous mterest m f ive to seven months.

The high cost of glass beads has resulted in interest m some states in extending the beads with cheaper materials. The rounded glass-like particles of Ottawa sand have been considered f o r this purpose Our 1949 tests indicated that there may be some meri t in this practice. The tests have also mdicated that beads or bead-sand mixtures do not significantly improve the pamt stripe durability The apparently longer service obtamed with beaded Imes seems to be due solely to prolonged vis ib i l i ty at night of the worn Imes. A l l results mdicate that mcreased durability m the paint must origmate m formulation modifications, such as vehicle improvement, reinforced pigmentation, or modified pigment-vehicle ratios.

22

TRAFFIC PAINT (Continued)

Because of the realization of possible differences of q;iinlon as to the relative importance of road service versus other factors, no attempt has been made i n this paper to suggest specific formulations. If those interested w i l l indicate the factors that are of greatest importance in their specific requirements, we w i l l be pleased to submit suggestions that we believe w i l l be of most value under the specific requirements.

State Highway Department J une 1950

QUESTIONNAIRE

ROAD MARKING TRAFFIC PAINTS

Please estimate the quantities of road marking t r a f f i c paints used by your department

Gallons 1949 1950

White White ref lectorized with glass beads YeUow Yellow ref lectorized with glass beads . . . . Other

Please check on what basis paints are purchased f o r use by your department.

Purchase Requirement Cost per Gallon Specification

Composition Performance

Other

Whatperiodof road service l i f e is obtamedfrom painted road stripesnow used by your department?

Type of Stripe Number al Months

White White plus glass beads Yellow Yellow plus glass beads Other

To aid us u following trends, indicate on which paint properties you mtend to place greater emphasis in the coming year. Please do so by numbering (e. g. 1, 2, 3, etc.) at least three but not more than l ive f r o m the following l i s t

Bleeding Resistance Storage stability Rate of dry Improved service l i f e VisibUlty

Day Night

Cost per gallon Other

What pigments do you prefer in white t r a f f i c paints? Please udicate by check marks in the following l i s t .

23

QUESTIONNAIRE (Contmued)

Non-beaded Beaded type type of paint of paint

Opaque White Pigments Titanium dioxide Titanium-calcium Lithopone Zinc Oxide No pjreference

Extender Pigments Magnesium silicate Diatomaceous earth Pumice Whiting No preference

Other

What vehicle types have you found most saUsfactory f o r t r a f f i c paints? Please indicate by check marks on the following l i s t .

Non-beaded Beaded type type of pamt of paint

Alkyd Copolymer-Chlorinated Paraff in . . . . Phenolic-Dispersion Resin Other Phenolic Resins Ester Gum Natural Gum Styrenated Oils Cumar ( for other than white pamt) . . . Other

Organization. Address

Name and t i t le of individual

P. S. Please attach a copy of the latest issue of your specification.

Pamt Manufacturer Tune 1950

QUESTIONNAIRE

ROAD MARKING TRAFFIC PAINTS

Please check whether your company manufactured road marking t r a f f i c paints of the following types during 1949:

White White f o r use with glass beads YeUow Yellow f o r use with glass beads Other

Which of the following pigments were used in substantial percentages in t r a f f i c paints made by your company in 1949?

24

QUESTIONNAIRE (ConUnued)

Non-beaded Beaded type type of paint of paint

Titanium dioxide Titanium-calcium Lithopone Zinc Oxide Magnesium silicate Diatomaceous earth Pumice Whiting Other

Which of the following vehicle types were used in t r a f f i c paints made by your company in 1949?

Non-beaded Beaded type type of paint of pahit

Alkyd Copolymer-Chlorinated Paraf f in . . . Phenolic-Dispersion Resin Other Phenolic Resins Ester Gum Natural Gum Styrenated Oils Cumar (for other than white paint) . . Other :

To aid us in following trends, indicate on which paint properties you Intend to place greater emphasis in the coming year. Please do so by numbering (e. g. 1. 2. 3. etc.) at least three but not more than f ive f r o m the following l i s t

Bleeding Resistance . Storage stability . . . Rate of dry Improved service l i f e VisibUlty

Day Night

Cost per gallon . . . Others

Based upon your direct eiqierience, what is the relative importance to service l i f e of the factors l isted below? Please rate their order of importance by numbering (e. g. 1, 2, 3, etc.) at least three but not more than f ive .

Importance Rating Application variables Type of hiding pigment Type of extender pigment Type of vehicle F i l m thickness Type of pavement surface .

Is t r a f f i c paint a substantial part of your business ? Yes No

Company

Address

Name and UUe of individual Date

N A T I O N A L R E S E A R C H C O U N C I L

The National Academy of Sciences is a private organization of eminent American Scientists, chartered under a special act of Congress in 1863 to "investigate, examine, experiment, and report on any subject of science or art. " The Academy maintains the National Research Council as its opera­ting agency.

The Council, organized with the cooperation of the scientific and techni­cal societies of America, enjoys the voluntary services of more than 2600 scientists making up over 400 standing committees, boards, and panels in all fields of the natural sciences; its membership includes representatives of business and industry. The Council provides adyisory and administra­tive services for research, and attempts to stimulate and coordinate re­search effort.

D I V I S I O N OF E N G I N E E R I N G AND I N D U S T R I A L R E S E A R C H

The National Research Council operates through eight divisions covering fundamental and applied natural sciences, as well as matters of inter­national relations in scientific research. The Division of Engineering and Industrial Research is concerned with the stimulation and correlation of research in a wide variety of fields in engineering and the applied sciences.

EXECUTIVE COMMITTEE - C. RICHARD SODERBERG, Chairman; WM. R. HAINSWORTH, Vice Chairman; FREDERICK M. F E I K E R , T. H. MacDONALD, PAUL D. FOOTE. EXECUTIVE SECRETARY - LOUIS JORDAN.

H I G H W A Y R E S E A R C H BOARD

The Highway Research Board is organized under the auspices of the Div­ision of Engineering andlndustrial Research of the National Research Coun­cil . Its purpose is to provide a national clearing house for highway research activities and information. The membership consists of 42 technical, educa­tional, industrial, and governmental organizations of national scope. As­sociates of the Board are firms, corporations, and individuals who are in­terested in highway research and who desire to further its work.

The purposes of the Board are: "To encourage research and to provide a national clearing house and correlation service for research activities and information on highway administration and technology, by means of: (1) a forum for presentation and discussion of research papers and reports; (2) committees to suggest and plan research work and to correlate and eval­uate results; (3) dissemination of useful information and (4) liaison and co­operative services."